Often these players give the computer applications video and audio codecs with which to work.

All of these things are up to date. I have 7 other computers set up the same and I can take this project and open it on another computer and it will publish just fine. I just tried it again and I got: "Export Settings are Invalid."

Let me ask this just to be sure....you say that you have 7 other computers set up the same and you can take this project and open it on another computer, and it will publish just fine. As for these other computers...

In spite of that...when you installed Premiere Elements 11 on the computer in question, did you install it to the default location or did you do a custom install?